Add SerdStatement

5 files changed, 199 insertions, 12 deletions

diff --git a/src/reader.c b/src/reader.c
index 9957e55c..0f97d237 100644
--- a/src/reader.c
+++ b/src/reader.c
@@ -20,6 +20,7 @@
 #include "node.h"
 #include "serd_internal.h"
 #include "stack.h"
+#include "statement.h"
 #include "system.h"
 #include "world.h"
 
@@ -127,8 +128,11 @@ emit_statement(SerdReader* const reader,
      (subject and predicate) were already zeroed by subsequent pushes. */
   serd_node_zero_pad(o);
 
-  const SerdStatus st = serd_sink_write(
-    reader->sink, *ctx.flags, ctx.subject, ctx.predicate, o, ctx.graph);
+  const SerdStatement statement = {{ctx.subject, ctx.predicate, o, ctx.graph},
+                                   &reader->source.caret};
+
+  const SerdStatus st =
+    serd_sink_write_statement(reader->sink, *ctx.flags, &statement);
 
   *ctx.flags &= SERD_ANON_CONT | SERD_LIST_CONT; // Preserve only cont flags
   return st;
diff --git a/src/sink.c b/src/sink.c
index 959a92b3..f78a0f18 100644
--- a/src/sink.c
+++ b/src/sink.c
@@ -16,6 +16,8 @@
 
 #include "sink.h"
 
+#include "statement.h"
+
 #include "serd/serd.h"
 
 #include <assert.h>
@@ -87,6 +89,15 @@ serd_sink_write_prefix(const SerdSink* sink,
 }
 
 SerdStatus
+serd_sink_write_statement(const SerdSink*          sink,
+                          const SerdStatementFlags flags,
+                          const SerdStatement*     statement)
+{
+  return sink->statement ? sink->statement(sink->handle, flags, statement)
+                         : SERD_SUCCESS;
+}
+
+SerdStatus
 serd_sink_write(const SerdSink*          sink,
                 const SerdStatementFlags flags,
                 const SerdNode*          subject,
@@ -99,10 +110,8 @@ serd_sink_write(const SerdSink*          sink,
   assert(predicate);
   assert(object);
 
-  return sink->statement
-           ? sink->statement(
-               sink->handle, flags, graph, subject, predicate, object)
-           : SERD_SUCCESS;
+  const SerdStatement statement = {{subject, predicate, object, graph}, NULL};
+  return serd_sink_write_statement(sink, flags, &statement);
 }
 
 SerdStatus
diff --git a/src/statement.c b/src/statement.c
new file mode 100644
index 00000000..51788e05
--- /dev/null
+++ b/src/statement.c
@@ -0,0 +1,134 @@
+/*
+  Copyright 2011-2020 David Robillard <d@drobilla.net>
+
+  Permission to use, copy, modify, and/or distribute this software for any
+  purpose with or without fee is hereby granted, provided that the above
+  copyright notice and this permission notice appear in all copies.
+
+  THIS SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+
+#include "statement.h"
+
+#include "caret.h"
+
+#include <assert.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+
+static bool
+is_resource(const SerdNode* const node)
+{
+  const SerdNodeType type = serd_node_type(node);
+
+  return type == SERD_URI || type == SERD_CURIE || type == SERD_BLANK;
+}
+
+bool
+serd_statement_is_valid(const SerdNode* const subject,
+                        const SerdNode* const predicate,
+                        const SerdNode* const object,
+                        const SerdNode* const graph)
+{
+  return subject && predicate && object && is_resource(subject) &&
+         is_resource(predicate) && serd_node_type(predicate) != SERD_BLANK &&
+         (!graph || is_resource(graph));
+}
+
+SerdStatement*
+serd_statement_new(const SerdNode* const  s,
+                   const SerdNode* const  p,
+                   const SerdNode* const  o,
+                   const SerdNode* const  g,
+                   const SerdCaret* const caret)
+{
+  assert(serd_statement_is_valid(s, p, o, g));
+
+  SerdStatement* statement = (SerdStatement*)malloc(sizeof(SerdStatement));
+  if (statement) {
+    statement->nodes[0] = s;
+    statement->nodes[1] = p;
+    statement->nodes[2] = o;
+    statement->nodes[3] = g;
+    statement->caret    = serd_caret_copy(caret);
+  }
+  return statement;
+}
+
+SerdStatement*
+serd_statement_copy(const SerdStatement* const statement)
+{
+  if (!statement) {
+    return NULL;
+  }
+
+  SerdStatement* copy = (SerdStatement*)malloc(sizeof(SerdStatement));
+  memcpy(copy, statement, sizeof(SerdStatement));
+  if (statement->caret) {
+    copy->caret = (SerdCaret*)malloc(sizeof(SerdCaret));
+    memcpy(copy->caret, statement->caret, sizeof(SerdCaret));
+  }
+  return copy;
+}
+
+void
+serd_statement_free(SerdStatement* const statement)
+{
+  if (statement) {
+    free(statement->caret);
+    free(statement);
+  }
+}
+
+const SerdNode*
+serd_statement_node(const SerdStatement* const statement, const SerdField field)
+{
+  return statement->nodes[field];
+}
+
+const SerdNode*
+serd_statement_subject(const SerdStatement* const statement)
+{
+  return statement->nodes[SERD_SUBJECT];
+}
+
+const SerdNode*
+serd_statement_predicate(const SerdStatement* const statement)
+{
+  return statement->nodes[SERD_PREDICATE];
+}
+
+const SerdNode*
+serd_statement_object(const SerdStatement* const statement)
+{
+  return statement->nodes[SERD_OBJECT];
+}
+
+const SerdNode*
+serd_statement_graph(const SerdStatement* const statement)
+{
+  return statement->nodes[SERD_GRAPH];
+}
+
+const SerdCaret*
+serd_statement_caret(const SerdStatement* const statement)
+{
+  return statement->caret;
+}
+
+bool
+serd_statement_equals(const SerdStatement* const a,
+                      const SerdStatement* const b)
+{
+  return (a == b || (a && b && serd_node_equals(a->nodes[0], b->nodes[0]) &&
+                     serd_node_equals(a->nodes[1], b->nodes[1]) &&
+                     serd_node_equals(a->nodes[2], b->nodes[2]) &&
+                     serd_node_equals(a->nodes[3], b->nodes[3])));
+}
diff --git a/src/statement.h b/src/statement.h
new file mode 100644
index 00000000..d780afed
--- /dev/null
+++ b/src/statement.h
@@ -0,0 +1,38 @@
+/*
+  Copyright 2011-2020 David Robillard <d@drobilla.net>
+
+  Permission to use, copy, modify, and/or distribute this software for any
+  purpose with or without fee is hereby granted, provided that the above
+  copyright notice and this permission notice appear in all copies.
+
+  THIS SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+
+#ifndef SERD_STATEMENT_H
+#define SERD_STATEMENT_H
+
+#include "serd/serd.h"
+
+#include <stdbool.h>
+
+typedef const SerdNode* SerdQuad[4];
+
+struct SerdStatementImpl {
+  SerdQuad   nodes;
+  SerdCaret* caret;
+};
+
+SERD_PURE_FUNC
+bool
+serd_statement_is_valid(const SerdNode* subject,
+                        const SerdNode* predicate,
+                        const SerdNode* object,
+                        const SerdNode* graph);
+
+#endif // SERD_STATEMENT_H
diff --git a/src/writer.c b/src/writer.c
index 8bbd6519..eaea9f3c 100644
--- a/src/writer.c
+++ b/src/writer.c
@@ -754,13 +754,15 @@ write_list_obj(SerdWriter* const        writer,
 }
 
 static SerdStatus
-serd_writer_write_statement(SerdWriter* const        writer,
-                            const SerdStatementFlags flags,
-                            const SerdNode* const    graph,
-                            const SerdNode* const    subject,
-                            const SerdNode* const    predicate,
-                            const SerdNode* const    object)
+serd_writer_write_statement(SerdWriter* const          writer,
+                            const SerdStatementFlags   flags,
+                            const SerdStatement* const statement)
 {
+  const SerdNode* const subject   = serd_statement_subject(statement);
+  const SerdNode* const predicate = serd_statement_predicate(statement);
+  const SerdNode* const object    = serd_statement_object(statement);
+  const SerdNode* const graph     = serd_statement_graph(statement);
+
   if (!is_resource(subject) || !is_resource(predicate) || !object) {
     return SERD_ERR_BAD_ARG;
   }